The atomic mass of an element is
a. a weighted average of the masses of an element’s isotopes.
b. twice the number of protons in one atom of the element.
c. the sum of the protons and neutrons in one atom of the element.
d. a ratio based on the mass of a carbon-12 atom.

explain

You are sitting on the beach and wondering about the properties of mechanical waves. describe them in terms of ocean waves.

Akg a of 55 m at an of 11 ? . if is at 98 km/h,be ?

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?